NEWS BRIEFS 2

IN-DEPTH ARTICLES ICs help implement a trim-free VCO (Part 2) 3

Maxim leads the way in ESD protection 7

NEW PRODUCTS Data Converters• 400ksps, multichannel, 10- and 12-bit ADCs offer low-power operation (MAX1280–87, 11

and more MAX1080–87)

Amplifiers and Comparators• Single-supply, 400MHz op amps with disable have ultra-low distortion (MAX4265–70) 12

and more

Analog Switches/Multiplexers• 2Ω quad SPST analog switches optimized for ±5V applications (MAX4677/78/79) 13

and more

Cable-TV IC• Upstream CATV amplifier outputs 66dBmV (MAX3509) 14Power-Management ICs• High-power step-up DC-DC converter integrates 10A switch (MAX1709) 15

and more

Filter ICs• Smallest 5th-order filters have lowest power (MAX7426/27) 16Battery Management ICs• World’s smallest Li+ battery charger in SOT23 (MAX1736) 17

and more

Supervisors• Quad voltage monitor requires no external components (MAX6338) 17

and more

Interface ICs• Triple RS-485 receivers include fault detection and ±15kV ESD protection (MAX3097E/98E) 18

and more

Signal-Conditioner IC• 16-bit signal conditioner for smart sensors operates at 2.4V (MAX1462) 19Hot-Swap Controller ICs• Current-limiting hot-swap controllers include autoretry (MAX4271/72/73) 20

and DualSpeed/BiLevel fault protection

Level Translators• Low-voltage SIM/smart-card level translators in µMAX package (MAX1840/41) 20

and more

Voltage References• Low-dropout, 20ppm/°C references deliver 5mA and require no output capacitors (MAX6061–67) 20

and more

Temperature Sensor ICs• First SOT23 dual-temperature comparators need no external components (MAX6505–08) 21Fiber-Optic ICs• 2.7Gbps multiplexer/buffer simplifies redundancy (MAX3781) 21

and more

Wireless ICs• Tiny chip-scale power amplifier for Bluetooth Class I applications (MAX2240) 22

and more

Volume Forty

MAXIM REPORTS RECORD REVENUES AND EARNINGS FOR THE FOURTH QUARTER AND FISCAL YEAR

Maxim Integrated Products, Inc., (MXIM) reported record net revenues of $256.6 million for its fiscal

fourth quarter ending June 24, 2000, a 60.9% increase over the $159.5 million reported for the same quarter a

year ago. Net income increased to a record $82.9 million in the fourth quarter, compared to $52.6 million last

year, a 57.8% increase. Diluted earnings per share were $0.26 for the fourth quarter, a 52.9% increase over the

$0.17 reported for the same period a year ago.

For the fiscal year, Maxim reported net revenues of $864.9 million, a 42.5% increase over the

$607.0 million reported last year. Net income increased 43.1% to $280.6 million in fiscal 2000, compared

to $196.1 million in fiscal 1999. Diluted earnings per share increased 37.5% to $0.88 in fiscal 2000 from

$0.64 in fiscal 1999.

Fourth quarter bookings were approximately $361 million, a 19% increase over the previous quarter’s

level of $304 million and an 83% increase over the fourth quarter of last year. Turns orders received in the

quarter were $108 million, a 13% increase over the $95 million received in the prior quarter (turns orders are

customer orders that are for delivery within the same quarter and may result in revenue within the same quarter

if the Company has available inventory that matches those orders). Bookings increased in all geographic

locations. There was significant growth in demand for the Company’s products targeting wireless and wired

communications, portable equipment, networks, and broad-based industrial applications. Fourth quarter

bookings by subcontract manufacturers exceeded third quarter levels.

Fourth quarter ending backlog shippable within the next 12 months was approximately $420 million,

including approximately $314 million requested for shipment in the first quarter of fiscal 2001. The Company’s

third quarter ending backlog shippable within the next 12 months was approximately $345 million, including

approximately $271 million that was requested for shipment in the fourth quarter. All of these backlog numbers

have been adjusted to be net of cancellations and estimated future U.S. distribution ship and debit pricing adjust-

ments.

Jack Gifford, Chairman, President, and Chief Executive Officer, commented on the results: “Fiscal 2000

was an excellent year for Maxim. Our bookings, revenues, earnings, and new product introductions grew to

record levels. Cash and short-term investments increased over $126 million during the year after we repurchased

$257 million of our common stock and invested $45 million in properties and facilities and $131 million in

equipment.”

Mr. Gifford continued: “Demand for our products has never been stronger and continues to exceed our

expectations. End market bookings have continued to increase over the past nine months due in large part to a

significant increase in new customer equipment applications utilizing Maxim products. The acceptance of our

new products, the breadth of our proprietary product lines, and the increasing demand for our products from

emerging markets also contributed to this growth. While bookings growth rates remain strong, turns orders as a

percent of bookings have come down from 41% in the fourth quarter of fiscal 1999 to more historical levels of

30% in the fourth quarter of fiscal 2000. We expect turns orders to stay at this level as customers are placing

more of their orders for delivery within the next three to six months. These orders remain within our 12-month

booking schedule.”

Mr. Gifford concluded: “We did an excellent job of meeting our product introduction goals this year. We

introduced a record 383 products during our product introduction year ending July 22, 2000, compared to 284

products last year. The 35% increase year over year bodes well for Maxim’s long-term growth expectations.

These products are key to our achieving future revenue growth targets and position Maxim as one of the premier

analog companies in the world.”

News Briefs

ICs help implementa trim-free VCO1

(Part 2)A new family of integrated circuits can ease the task ofdeveloping compact, fixed-frequency, voltage-controlledoscillators (VCOs) for IF applications.

Designing a VCO for use with a fixed intermediate-frequency (IF) can be daunting. Fortunately, VCO ICsfrom Maxim (MAX2605–MAX2609) can simplify thetask. Compared to conventional discrete-device VCOs, theMaxim parts cost less and require less PC board space.

In a traditional IF VCO design, the oscillator core andoutput buffer stage are formed by discrete transistors,resistors, capacitors, and inductors (Figure 1). The tank isbuilt from a network consisting of the frequency-settinginductor, varactors, coupling capacitors, and feedbackcapacitors. The output stage uses reactive elements to matchthe output impedance to a particular load impedance.

To ensure a successful design, the component values mustnot only establish a desired nominal oscillationfrequency, they must also guarantee an adequate tuningrange, proper biasing, oscillator startup under all condi-tions, and proper output-stage performance. Problems can

occur even with a good first-order design because of thetrade-offs that exist among current consumption, startupmargin, frequency tuning range, and phase noise.

A major disadvantage of discrete IF VCO designs is theamount of PCB area needed. Much effort must beexpended in optimizing the layout to below 6mm x 10mm.Furthermore, the PCB layout has a critical effect on theVCO’s performance and design accuracy. The layoutcontains parasitic capacitances and inductances that affectthe oscillation frequency and must therefore be taken intoaccount to implement the oscillator properly. Parasiticelements often cause an undesired shift in the nominaloscillation frequency, which causes greater design-centering errors and ultimately forces a need for greatertuning range to account for those errors.

The MAX2605–MAX2609 IF VCO family offers a betteralternative. These five ICs are designed for low-power,fixed and single-frequency portable wireless applicationswith IF frequencies in the 45MHz to 650MHz range.Much of the required circuitry is included on chip; onlythe tank inductor (which establishes the oscillationfrequency) is external.

Once you choose the correct external inductance value,the IC guarantees that some level within the tuning-voltage range (+0.4VDC to +2.4VDC) will tune in thecorresponding frequency. The IC’s tuning-voltage inputcan be driven directly from the loop-filter outputfollowing a phase-locked loop (PLL). MAX2605–MAX2609 ICs are designed for supply voltages in the+2.7VDC to +5.5VDC range, and the supply voltageconnection does not require special regulation for properoperation. Each IC comes in a tiny, 6-pin plastic SOT23package (Figure 2).

3

Figure 1. This schematic shows an IF VCO implemented with discretecircuit elements.

TUNE

OUT

VCC

Figure 2. The MAX2605–MAX2609 IF VCO ICs come in a 6-pin surface-mount SOT23 package designed to occupy minimum PCB space.

GND

OUT-TUNE

1 6 OUT+

5 VCC

IND

2

3 4

MAX2605–MAX2609

1A similar article appeared in the August 2000 issue of Microwaves & RF magazine.

The MAX2605 tunes from 45MHz to 70MHz, with -117dBc/Hz phase noise at 100kHz from the carrier. Forthe other devices, these parameters are: 70MHz to150MHz tuning with -112dBc/Hz phase noise at 100kHzfrom the carrier (MAX2606), 150MHz to 300MHz with -107dBc/Hz (MAX2607), 300MHz to 500MHz with -100dBc/Hz (MAX2608), and 500MHz to 650MHz with-93dBc/Hz (MAX2609).

The frequency tuning range, biasing, startup, and otheroscillator characteristics are all managed within the IC,eliminating the design headaches typically associatedwith VCO design. An on-chip varactor and capacitorssimplify IF VCO design by eliminating the need forexternal tuning elements. A graph of inductance versusoscillation frequency (see the MAX2605–MAX2609 datasheet) further simplifies the task of choosing an externalinductor.

The MAX2605 family provides several important newbenefits for RF designers. The ICs are designed to createVCOs that are trimless and do not need external adjust-ments. To accommodate the anticipated range of systemIFs found in dual-conversion systems, they are designedto cover a wide range of application frequencies. Inaddition, they have a flexible output interface to helpreduce the cost of IF VCOs and shrink the size of thefinal design.

Because the MAX2605–MAX2609 represent a newconcept in VCOs, they required a fundamentally newcircuit approach to achieve the product objectives. Maximdevised an oscillator scheme based on the reliable andflexible Colpitts oscillator structure. This topology was

adapted so that all the oscillator circuit elements (exceptthe inductor) could be integrated within the IC.Integrating nearly the entire oscillator on chip provides allthe desired operating objectives of a good VCO: properoscillator startup, wide frequency range, required tuningcharacteristics for trimless operation, controlled currentconsumption, and biasing that was independent oftemperature and the power-supply voltages.

An off-chip inductor allows the VCO to be applied over avery wide range of operating frequencies. On-chip capac-itance remains the same, but changing external induc-tance values modifies the resonant frequency of the oscil-lator tank circuit. If the inductor has a minimum qualityfactor (Q), the phase-noise and startup behavior can beguaranteed (Figure 3).

To implement this new approach, the IC technologyneeded a full complement of active and passive elementsto support construction of the oscillator circuit shown.Specifically, the process technology had to provide high-frequency transistors, high-Q capacitors, high-Q varactordiodes with high capacitance ratios, and PNP or PMOSdevices.

The MAX2605–MAX2609 are fabricated on a siliconBiCMOS process developed specifically for RFICs thatinclude monolithic oscillator structures. This processfeatures PNP, NMOS, and PMOS devices, NPN transis-tors with transition frequencies (fT) of 25GHz, low-series-resistance varactor diodes with better than 2:1capacitance ratio (for tuning voltages from 0.4V to 2.4V),very high-Q metal-insulator-metal (MIM) RF capacitors,precision thin-film resistors, and three layers of metal.

Figure 3. This simplified circuit diagram of the MAX2605–MAX2609 VCO ICs shows that only an external inductor is necessary to complete the resonant circuit, which sets the oscillation frequency.

GND

TUNE

LF

OUT+

OUT-

VCO IC

INDBIAS

VCC

AMPLITUDECONTROL

MAX2605–MAX2609

4

This full complement of devices allowed implementationof the complete IC. The VCO design required careful andextensive computer simulations, including multipledesign iterations between various aspects of performanceto ensure that all specifications and requirements could beguaranteed over all operating conditions.

Finally, to guarantee that the oscillator possessed a suffi-cient frequency-tuning range to account for the shift inoperating frequency caused by component tolerances,Maxim elected to perform production testing on thedevices and guarantee a set of frequency limits. Theselimits provide MAX2605–MAX2609 users with a guar-anteed set of high- and low-frequency tuning limits(fMAX and fMIN), in which passing ICs have a frequencyof oscillation (fOSC) ≤ fMIN at a tuning voltage (VTUNE)of 0.4V, and fOSC ≥ fMAX at VTUNE = 2.4V. Assumingan external inductor with ±2% tolerance, includingtemperature drift, and a small design centering error(<0.5%), this testing guarantees that the VCO alwaystunes to the operating frequency selected by the inductor,without adjustment of the external inductance value. Theresult is a trimless VCO design.

MAX2605–MAX2609 applications are highly simplifiedand easy to understand. Two simple steps are involved:

1) Select and implement an external inductance to set thedesired oscillation frequency.

2) Resistively or reactively match the output stage to theload (Figure 4).

The nominal operating frequency (fNOM) desired for theVCO is determined solely by the effective external induc-tance value at IND (pin 1), as determined by a curve(Figure 5).

The inductance value (LF) required for a desired operatingfrequency will not necessarily coincide with any of thestandard values for surface-mount-technology (SMT)inductors, which typically increase in steps that differ by afactor of approximately 1.2. To achieve the desired valuein such cases, the inductance must be constructed fromtwo inductors, LF1 and LF2. LF1 should be chosen as thenearest standard value below the desired value. Then,choose LF2 as the nearest standard value just less than LF - LF1. LF1 should adhere to the minimum Q require-ments, but LF2 can be implemented as a lower cost thin-film SMT type. Because its value is less than 20% of thetotal, its lower Q has only a small effect on the overall Q.

It is also permissible to adjust the total inductance valueby implementing small amounts of inductance with PCBtraces. For MAX2608/MAX2609 circuits, the inductancevalue for LF2 is sometimes more precisely implementedas a PCB trace shorted to ground than as an SMTinductor. Once the required inductance value is estab-lished at pin IND, the VCO is guaranteed to tune to thisoscillation frequency over all component variations,operating temperatures, and supply voltages.

MAX2605–MAX2609 VCOs include a differential outputamplifier after the oscillator core. The amplifier stageprovides valuable isolation and offers a flexible interfaceto IF functions such as a mixer and/or a PLL prescaler.

5

Figure 4. This simple schematic represents a typical application for the MAX2605–MAX2609 VCO IC.

C1

OUT+

OUT-

TO PLL/MIXER THROUGH ARESISTOR ORCAPACITOR DIVIDERNETWORK

C2

R2

R1

TUNE

FROM PLL LOOPFILTER OUTPUT

1 6

5

VCC

LF

2

3 4

The output can be taken single ended or differentially, butthe maximum output power and lowest harmonic outputis achieved in the differential-output mode. Both open-collector outputs (OUT- and OUT+) require a pullupelement to the collector voltage (VCC). The output stagemay be applied with a pullup resistor or inductor. Apullup resistor is the most straightforward method offorming an interface to the output and works well inapplications that operate at lower frequencies or requireonly a modest voltage swing.

A reactive power match is required for operating frequen-cies above the 3dB bandwidth of the load-resistance/capacitance network and/or when a greater voltage swingor output power is desired. The matching network is asimple circuit with a shunt inductor and series capacitor.To provide DC bias for the output stage, the inductors areconnected from OUT- and OUT+ to VCC, and the seriescapacitors are connected from OUT- and OUT+ to theload. Values for the inductor and capacitor are chosenaccording to the operating frequency and load impedance.The output is applied like any conventional differentialoutput. The only constraints are the need for a pullup toVCC and a limit to the voltage swing at OUT- and OUT+.

A comparison of the design time needed to apply eachapproach reveals a dramatic difference. The classical/discrete approach shown is very design intensive, and thesuccessful development of a discrete IF VCO may requiremany weeks. Several iterations are likely before reachinga robust, manufacturable design. On the other hand, theMAX2605–MAX2609 let you design the VCO inminutes and then verify and test it in an afternoon!

Because the MAX2605–MAX2609 solve the problems offrequency tuning range, biasing, and startup, theycompletely eliminate the difficult tasks typically associ-ated with a VCO design. You need only select an externalinductance value based on the desired oscillationfrequency, and the output load. This task is easily accom-plished by reading the desired inductance value from agraph supplied on the MAX2605–MAX2609 data sheet.

In bill-of-materials cost, the MAX2605–MAX2609 arecomparable to the traditional discrete IF VCOs. As formanufacturing, Maxim’s parts may support even lessexpensive IF VCOs—as a consequence of having fewercomponents to place and a $0.03 savings per component.

6

Figure 5. This plot contains values of the required total tuning inductance (LF) as a function of desired oscillation frequency (150MHz to 300MHz) for the MAX2607 VCO IC.

MAX2607* REQUIRED INDUCTANCE vs. DESIRED VCO FIXED FREQUENCY

160

150

140

130

120

110

100

90

80

70

60

50

40

REQU

IRED

INDU

CTAN

CE (n

H)

160 170 180 190 200 210 220 230 240 250 260 270 280

INDUCTOR VALUEMOUNTED ON EV KIT

30150 290 300

170

EFFECTIVE INDUCTANCEFROM IND TO GND

MEASUREMENT CONDITIONSVCC = 2.75V, TA = +25°C,

RLOAD = 100Ω||50Ω (100Ω RESISTIVE PULLUP PARALLELED WITH 50ΩVNA IMPEDANCE), UNUSED OUTPUT TERMINATED IN 50Ω,

PCB PARASITIC SHUNT CAPACITANCE (IND TO GND) = 0.45pF

THE INDUCTANCE LISTED IS THE PRECISE NOMINAL INDUCTANCE VALVEREQUIRED FROM IND TO GND IN ORDER TO GUARANTEE THE VCO

CAN TUNE TO THE DESIRED FIXED FREQUENCY, OVER ALL OPERATINGCONDITIONS AND WORST-CASE COMPONENT

VALUES (±2% INDUCTOR AND IC PROCESS VARIATION).

DESIRED VCO FIXED FREQUENCY (MHz)*FIGURE FROM MAX2607 DATA SHEET

Maxim leads theway in ESD protectionElectrostatic discharge (ESD) is often found to be the rootcause of equipment failure on the factory floor and in thefield. Such failures can be difficult to track down whenthey masquerade as other types of failures, as they oftendo. In manufacturing, for instance, the yield loss at finaltest might be traced to a bad component or subassemblyand then (with further investigation) associated with anOEM manufacturing or test process that subjects the partto ESD.

Early field failures and post-installation problems in indus-trial equipment are often caused by ESD during installation.The most insidious ESD damage is that which degrades theperformance of an instrument but (at least initially) does notaffect its operation in an obvious way. Such events cancause erratic or nonlinear operation immediately but maynot produce a “hard” failure for months or years.

This article explains how to protect your products fromESD. It outlines the standard test methods required by theelectronics industry, offers some common techniques toprotect against ESD, and highlights some of Maxim’sESD-protected devices. With careful design, thesedevices can improve product quality while saving money and your company’s reputation.

Damage potential

A photomicrograph (Figure 1) shows the damagesustained by a competitor’s RS-232 interface IC afterexposure to an ESD strike of 15kV (a common test level).The result is a gross failure that is easily visible becausethe overstress actually vaporized metalization on the chip.In other cases, the investigation of invisible failures in thegate-oxide layers or buried layers requires careful removal

of metalization or other layers. ESD strikes can also findpaths into the core of an instrument. Somewhat like alightning strike, ESD will course through the circuit untilits energy is dissipated, often with unexpected effects.

Where does high voltage come from?

Mechanically separating two materials creates electro-static charge. The surfaces of these otherwise neutralmaterials are electrically double layered to varyingdegrees, meaning that the outer layer might have amajority of electrons balanced by positive charge in thebulk of the material. Other materials exhibit the oppositesurface charge. When materials with opposite surfacecharges come in contact, a transfer of electrons leaves onematerial with a net negative charge and the other with anet positive charge. Called triboelectric generation, thiseffect is the basis of static generation and transfer.

The triboelectric series shown in Table 1 positionsmaterials like glass and nylon at the positive end andsilicon and teflon at the negative end. The materials’conductivity also affects their ability to build up a surfacecharge. For many materials, the conductivity or surfaceresisitivity is strongly dependent on humidity. Lowhumidity promotes low conductivity, which maintains thelocalized charges by preventing them from moving.

Table 1. Triboelectric seriesAIR (MOST POS.) FUR SEALING WAX ORLON

HANDS LEAD HARD RUBBER SARAN

ASBESTOS SILK NICKEL, COPPER POLYURETHANE

RABBIT FUR ALUMINUM BRASS, SILVER POLYETHYLENE

GLASS PAPER GOLD, PLATINUM PVC

MICA COTTON SULFUR KEL-F (CTE)

HUMAN HAIR STEEL ACETATE, RAYON SILICON

NYLON WOOD POLYESTER TEFLON (MOST NEG.)

WOOL AMBER CELLULOID

In the real world, static high voltage is usually producedby the interaction of people and their surroundings.Imagine a person sitting at a formica table in a plasticchair, wearing wool slacks and socks, leather shoes, acotton shirt, and silk tie. This soup of triboelectricmaterials defies quantitative analysis, but one can imagineit responsible for some serious charge build-up. Severalaccepted models describe a charged human body fordifferent situations. The most generic model (Figure 2)assumes a 100pF capacitance charged to 15,000V and a1500Ω series resistance.

7

DIELECTRICFAILURE &CONTACT

SPIKING

SPLATTEREDALUMINUM

ELECTRO-THERMALMIGRATION

RUPTUREDPASSIVATION

Figure 1. This photomicrograph shows gross ESD damage to an unprotected RS-232 receiver.

Test methods and standards

Two methods commonly used for testing the ESD suscep-tibility of integrated circuits have been adapted for end-equipment testing as outlined in the next section. Theoldest method, MIL-STD-883 Method 3015.7, wasdeveloped as an aid in understanding the precautionsnecessary for packaging and handling ICs. This methodtests each package pin against other groups of pins andclassifies the device according to the lowest voltage forwhich failure occurs.

The applied signal in this test is a current waveformderived from a circuit called the Human Body Model(Figure 2), which simulates the capacitance and sourceimpedance typical of a human body. Circuit layout iscritical because the actual waveform delivered at the ICdepends also on parasitic inductance and capacitanceassociated with the test connections and PC board. Theresulting current waveform represents the ESD thatoccurs when a person touches an object such as an IC.

The other method, which differs from the above only inthe values for R and C, was developed by the ElectronicIndustries Association of Japan (EIAJ). Called IC-121 andbased on a circuit called the Machine Model (Figure 3), itapplies a current waveform similar to that produced whenan IC makes contact with its handling machinery. Bymimicking the ESD events caused by charges that accu-mulate on moving parts, the waveform simulates the staticdischarges seen during machine assembly.

The two methods are complementary, so you shouldn’tchoose one over the other. Because ESD can affect ICsduring manufacturing, during PC board assembly, andafter the end product is put into service, a test based onthe Human Body Model and the Machine Model togetherprovides adequate assurance regarding the IC’s tolerancefor the rigors of manufacturing and product life.

These two tests are for ICs. Other specific tests governthe exposed interfaces of end equipment. For example, ICpins exposed to the outside world through connectors canencounter ESD even when mounted on a PC board withinan enclosure. ESD exposure is less likely for the otherpins, which are connected to circuitry on the board.

For this class of IC, a test method such as Method 3015.7(which tests pin combinations) does not provide anadequate representation of ESD susceptibility for theinput /output (I /O) pins. The Machine Model and Method3015.7, which offer ratings according to the lowestvoltage failure on any pin, may not do justice to thehigher levels of internal ESD protection required by theI /O pins (and provided by some manufacturers). A devicemight have I /O pins that withstand ±15kV and non-I /Opins that fail at ±2kV. With the methods described above,the resulting ESD rating could be less than ±2kV.Fortunately, however, better test methods are nowavailable for rating I /O pins.

New ESD tests for I/O ports

An I /O port allows communication with other pieces ofequipment. I /O ports for ICs comprise logical groups ofpins that give access to equipment external to the systemcontaining the IC. These pins are subject to staticdischarge and other abuse as operators connect anddisconnect cables from the system. For the I /O pins of anexternal interface IC, an ideal test method for ESDsusceptibility should:

• Test the I /O pins only in ways that simulate exposureto ESD events in actual equipment.

8

100pF CHARGE TO 15kV

1500Ω

Figure 2. When discharged, this circuit (the Human Body Model)produces a very fast rise time with current peaks of15kV/1.5kΩ—over 10A!

TERMINAL C

TERMINAL D

TERMINAL B

TERMINAL A

S1

S2

R2R1

C1REGULATED

HIGH-VOLTAGESUPPLY

DUTSOCKET

CURRENTPROBE(NOTE 6)

SHORT

MACHINEMODEL

(IC-121, EIAJ)

IEC1000-4-2

1M 50M TO 100M

0 330

200 ± 5% 150

COMPONENT

R1 (Ω) 1M TO 10M

R2 (Ω) 1500 ± 1%

C1 (pF) 100 ± 10%

Figure 3. Substituting different component values as shown yieldsdischarge circuits known as the Human Body Model, theMachine Model, and the IEC 1000-4-2 Model (humanholding a metallic object).

HUMAN BODY MODEL(MIL-STD 883,

METHOD 3015.7)

• Apply test waveforms that model electrostaticdischarges produced by the human body. Differentcircuit models specify different values of amplitude,rise/fall time, and transferred power.

• Test the IC with and without power applied.

• Define IC failures to include latchup (a momentary lossof operation) as well as catastrophic or parametricfailure. Latchup is considered a failure mechanismbecause, if left undetected, it can lead to reliabilityproblems and system malfunctions.

Two methods—both compliant with the requirementslisted—have seen increasing use by equipment manufac-turers in testing the ESD susceptibility of I /O ports(Figure 3). The first is a modification of Method 3015.7,MIL-STD-883. It makes use of the same circuit modeland waveform as the original method but applies ESDpulses only to the I /O pins of a device. Its intent is tosimulate the fault currents seen by an IC installed on aboard and operating in the target system. The secondmethod is IEC 1000-4-2, which has become the worldstandard. It specifies a higher capacitance and lower resis-tance than that specified in Method 3015.7. IEC 1000-4-2is universally applied in testing end-equipment interfaces(Table 2). Note that Maxim’s analog switches and RS-232/RS-485 interface ICs comply with these ESDstandards, without the need for external components.

ESD-protection methods

Protecting an interface from ESD damage is thedesigner’s responsibility. The industry offers a choice ofseveral methods, each with certain strengths and weak-nesses. Lots of misunderstanding and black magicsurround ESD remedies, and the following discussion isintended to dispel some of that mystery.

Capacitor protection

This method is common in high-volume consumer andautomotive equipment. It protects the input pins with a

simple shunt capacitor from input to ground. The idea isthat a capacitor of sufficient value will absorb an ESDdischarge without exceeding the ESD rating of theattached IC pin. To illustrate, consider an IC pin exposedto the outside world, with an ESD rating of 2kV.

The IEC 1000-4-2 Model specifies a 150pF capacitancecharged to 15kV. If a 1500pF capacitance is added to theexposed pin, it will charge to a maximum equal to 1/10 ofthe test voltage (1.5kV). Because this level is below theIC’s ESD-protection rating, one assumes that all is well.This method is widely used, but it involves a simplisticview of the physics involved. It provides some protectionif you exercise extreme care in the circuit layout,provided that the circuit operation is not affected by eitherthe necessary capacitance or parasitic inductance. Toemphasize the sensitivity to layout, consider that a 1cmtrace on a PC board has about 7nH of inductance. When a30A current pulse with 1ns rise time (the IEC 1000-4-2waveform, Figure 4) is applied to 7nH, it produces avoltage spike of 210V for each centimeter of ground path.

Resistor protection

Resistor protection is added in series to the interface pins.This resistance limits peak currents and helps dissipate someof the power in a transient. Similar to capacitor protection,precautions should be taken to ensure that circuit operation isnot adversely affected by this increased impedance. Anothercaveat is that resistors themselves can be ESD sensitive.Metal-film resistors are fabricated with methods similar tosemiconductor metalization and often have similar ESD limi-

9

IEC 1000-4-2COMPLIANCE

LEVEL

MAX TEST VOLTAGE, CONTACT DISCHARGE

(kV)

MAX TEST VOLTAGE, AIR GAP DISCHARGE

(kV)

1 2 22 4 43 6 84 8 15

Table 2. IEC 1000-4-2 classification of four voltage ranges

100%

I

90%

1 AT 30ns

1 AT 60ns

10%

30ns60ns

tR = 0.7ns TO 1ns

t

Figure 4. Parameters for this ESD waveform (rise time, peak current,amplitude at 30ns, and amplitude at 60ns) are specified byIEC 1000-4-2.

tations. The parasitic capacitance of these series resistors canalso be an issue. A narrow spike, through even a few pico-farads, can wreak havoc on an IC input.

Resistor-capacitor protection

This approach is a hybrid of the R and C protection tech-niques discussed above. Having two components perinterface pin consumes PC real estate while increasingcosts and decreasing reliability. RC networks are oftenused for EMI suppression in concert with ferrite beads orfeedthroughs.

MOVs and TransZorb™ protection

Adding metal-oxide varistors (MOVs) or siliconavalanche suppressors (TransZorbs) to I /O pins can bevery effective. They tend to be expensive, they can belarge, and they can add unwanted capacitance to aninterface. Similar to capacitor protection, these devicesrequire low-inductance (short) paths to ground.

Layout guidelines for enhancing ESD protection

• Follow standard analog layout techniques, placing allbypass and charge-pump capacitors as close as possibleto the IC (interface ICs especially).

• Include a ground plane on the PC board.

• Place the protection or IC as close to the I/O port aspossible.

Protection internal to Maxim ICs

Maxim has invested a substantial effort in developing ICswith internal ESD protection. Starting with RS-232 andRS-485 interface ICs, these protected devices nowinclude several analog switches and the MAX681_ familyof switch debouncers. All withstand the application ofIEC 1000-4-2 ESD events directly to their I/O pins.Maxim believes this is the best way to control ESD in asystem. It is robust, readily available, requires no externalreal estate, and costs less than most alternatives.

Maxim offers a variety of ESD-protected RS-232 interfaceICs, representing every useful combination of drivers andreceivers. Included are ultra-low-power RS-232 devicesincorporating Maxim’s AutoShutdown™ feature. Severalnew innovations have been introduced in the area of ESD-protected RS-232 interface devices this year. For example,single RS-232 receivers and transmitters with full ESDprotection in tiny SOT packages (the MAX318_ series) canbe real problem solvers in small portable equipment.

Also scheduled for introduction is a unique ESD-protectedinterface for data cables. Data cables for cellular phonesusually include an RS-232 interface in the cable rather thanthe phone. Thus, ESD protection for this application isrequired not just on the RS-232 side of the interface IC buton the logic side as well. The MAX3237E is the only ICavailable that offers a solution to this problem. It offers acomplete 5-transmitter, 3-receiver interface (like amodem). Maxim has plans to introduce additional RS-232interface ICs with this double ESD protection for otherapplications such as PDA cradles and other phone configurations.

RS-485 interfaces

Maxim is also the leader in ESD-protected RS-485 inter-faces. After pioneering the use of ESD protection for suchdevices, Maxim offers 17 products in this area, with manymore on the way. Significant in the last year was the intro-duction of the MAX3095/MAX3096, which extendMaxim’s robust ESD structures and low-power operationto the venerable 26LS32 quad-receiver pinout. Alsoreleased in the last year is a full line of 3.3V, ESD-protected, RS-485 interface ICs. Maxim innovations for theMAX348_E family, for example, include ESD protection,fractional unit loads, slew-rate limiting, and low power.

Analog switches

Maxim was the first IC company to recognize the valueof ESD protection for analog switches and multiplexersthat serve as the interface to external systems in a host ofapplications for which ESD protection is necessary. Firstwas a series of ESD-protected switches and multiplexers.This series includes several low-voltage ICs with ±15kVESD protection: an 8-to-1 CMOS analog multiplexer with4051 pinout (MAX4558), a 4-to-1 CMOS analog multi-plexer with 4052 pinout (MAX4559), a triple SPDTswitch with 4053 pinout (MAX4560), and an SPST,CMOS analog switch with 4066 pinout (MAX4551).

A second series of devices, in SOT23 packages with±15kV ESD protection, includes a single SPST-NOswitch (MAX4568), an SPST-NC switch (MAX4569),and an SPDT switch (MAX4561).

10

TransZorb is a trademark of General Semiconductor Industries, Inc.AutoShutdown is a trademark of Maxim Integrated Products.

References

1. Maxim Engineering Journal #25, “ESD Protection for I/O Ports.”

2. Electrostatic Discharge Control, Owen J. McAteer, McGraw Hill. 1989. ISBN 0-07-044838-8.

11

NEW PRODUCTS

Octal, 13-bit voltage-output DAC has parallel interface

The MAX5270 includes eight 13-bitvoltage-output DACs and three separatepairs of differential reference inputs on onemonolithic chip. For a reference voltage of+4.096V to GND, the correspondingoutput voltages have a full-scale range of0V to +8.192V. The output amplifiersremain stable while driving capacitiveloads up to 10,000pF, and the output glitchamplitudes can be as low as 30mV during

major-carry transitions. The device alsooffers low output noise (120nV/√Hz) andlow DC crosstalk (75µV).

The MAX5270 accepts 13-bit parallel-loaded data from the external bus into oneof eight input registers, under the controlof WR, CS, and the DAC address pinsA0–A2. The DAC outputs are updatedupon receipt of new data into the DACregisters. Each DAC output is bufferedwith a gain-of-two amplifier, into whichan external DAC offset voltage can beinserted through the SYSGND pins.

The MAX5270 is available in a space-saving 44-pin MQFP package, with pricesstarting at $22.50 (1000–up, FOB USA).

400ksps, multichannel, 10- and 12-bit ADCs offer low-power operation

The MAX1280–MAX1287 (12-bit) andMAX1080–MAX1087 (10-bit) analog-to-digital converters (ADCs) offer 1, 4, and 8channel options and 400ksps sampling rates.Their serial interface connects directly toSPI™, QSPI™, and MICROWIRE™ deviceswithout external logic. Ideal for portable dataacquisition and battery-powered applications,these ADCs combine low-power operation(1.5mA at 100ksps), excellent dynamic perfor-mance (SINAD > 70dB), and high speed(400ksps) in packages as small as an 8-pin SO.

The analog inputs of these ADCs are softwareconfigurable for unipolar/bipolar and single-ended/differential operation. The full-scaleanalog input range is set by the internal +2.5Vreference or by an externally applied referencevoltage between 1V and VDD. Operating froman analog supply voltage in the +2.7V to +5.5Vrange, the ADCs draw only 2.5mA at 400ksps.Software power-down modes lower currentdraw to 1.5mA at 100ksps. At even lower datarates, supply current drops to <10µA.

The MAX1280–MAX1287 and MAX1080–MAX1087 ADCs are available in 8-pin SOpackages and 16- and 20-pin TSSOP packages,with prices starting at $3.88 (1000–up, FOBUSA).

SPI/QSPI are trademarks of Motorola, Inc.

MICROWIRE is a trademark of National SemiconductorCorp.

Smallest available dual 8-bit DAC fits in SOT23

The MAX5222 contains two buffered,voltage-output, 8-bit DACs in a 3x3mm 8-pin SOT23 that requires 70% less boardspace than comparable devices in 8-pinSO packages. Operating from a single2.7V to 5.5V supply, the MAX5222’sultra-low power consumption and smallsize make it ideal for portable and battery-powered applications. Supply current is<1mA and drops below 1µA in shutdownmode. Shutdown further reduces systempower consumption by disconnecting thereference-input pin from the REF pin.

The MAX5222’s 3-wire serial interfaceallows clock rates up to 25MHz. Theserial input shift register is 16 bits long (8bits of DAC input data and 8 bits for DACselection and shutdown control). DACregisters can be loaded independently orin parallel, at the positive edge of chipselect. Both DAC outputs can source andsink 1mA while swinging to within100mV of ground or VDD. Prices start at$1.25 (1000–up, FOB USA).

12- and 10-bit ADCs include ±1°C temperature sensor

The MAX1298/MAX1299 and MAX1098/MAX1099 are the first 12- and 10-bitADCs capable of measuring voltage, localtemperature, and remote temperaturewithout additional circuitry. Each includesa ±1°C accurate sensor for local tempera-ture measurement as well as signal-condi-tioning circuitry that enables the use ofdiode-connected transistors for remotetemperature measurements.

The analog inputs can be configuredthrough the serial interface for temperaturemeasurement, single-ended voltagemeasurement, and fully differential voltagemeasurement. In the temperature-sensingmode, internal bias currents pass througheither the internal sensor or an externaldiode-connected transistor. No additionalcircuitry is required for temperaturemeasurements.

The MAX1099/MAX1299 operate from asingle +3V analog supply, and theMAX1098/MAX1298 operate from asingle +5V analog supply. Quiescentcurrent is only 250µA, and softwarepower-down modes further reduce thesupply current to <10µA at lower samplingrates. All are available in 16-pin SSOPpackages, with prices starting at $2.68(1000–up, FOB USA).

DACLATCH

ADAC A

DACLATCH

BDAC B

SCLK

DIN REFVDD16

-BIT

SHI

FT R

EGIS

TER

MAX5222

VOUTA

VOUTB

GND

CS

12

NEW PRODUCTS3V/5V, 250MHz ADC buffer amplifiersachieve -87dBc SFDR at 5MHz

The MAX4285–MAX4288 and MAX4387/MAX4388 are single-supply, 250MHz opamps in a space-saving 6-pin SOT23package. The combination of single 3V/5Voperation, wide bandwidth, low -87dBcSFDR (at 5MHz), and fast 6ns settling time(to 0.1%) makes these op amps ideal for useas preamps and drivers for a variety of high-speed, single-supply ADC applications incommunications and instrumentation.

These amplifiers operate from a single+2.85V to +6.5V supply or dual ±1.425Vto ±3.25V supplies, and their inputcommon-mode range includes ground.They have a large-signal -3dB bandwidthof 200MHz, a slew rate of 350V/µs, andan output current-drive capability up to100mA. In addition, the MAX4285/MAX4286/MAX4288/MAX4388 havelow-power disable modes that reducesupply current and place the outputs in ahigh-impedance state, making them idealfor multiplexing applications.

The MAX4285/MAX4286 single ampli-fiers with disable are offered in space-saving 6-pin SOT23 and 8-pin SOpackages. The MAX4287/MAX4387 dualamplifiers are offered in 8-pin µMAX andSO packages, and the MAX4288/MAX4388 dual amplifiers (with disable)are offered in 10-pin µMAX and 14-pinSO packages. Prices start at $0.89(1000–up, FOB USA).

1.8V, rail-to-rail I/O op amps deliver 120dB AVOL and drive 2kΩ loads

The MAX4292/MAX4294 (dual/quad) opamps have Rail-to-Rail® inputs andoutputs. Operating from a single +1.8V to+5.5V supply, these op amps are ideal forone- and two-cell, low-power, portableapplications. A 100dB power-supply

rejection ratio allows these op amps to beoperated directly from a single lithium-ion(Li+) cell or from two to three NiCd,NiMH, or alkaline cells, withoutproducing an excessive output error as thecell voltage decays.

The MAX4292/MAX4294 achieve a120dB open-loop gain while drawing only100µA of supply current per amplifier.They achieve a 500kHz gain-bandwidthproduct, drive 2kΩ loads, and are unity-gain stable for capacitive loads up to100pF. Superior open-loop gain, excellent

load-driving capability, and an input offsetvoltage of 400µV make these amplifiersideal for use as reference buffers.

The MAX4292 is offered in space-saving8-pin µ MAX and SO packages. TheMAX4294 is offered in miniature 14-pinTSSOP and SO packages. Prices start at$0.23 per amplifier (quad, 50,000–up,FOB USA).

Rail-to-Rail is a registered trademark of NipponMotorola, Inc.

Single-supply, 400MHz with disablehave ultra-low distortion

The MAX4265–MAX4270 are single-supply, voltage-feedback op amps capableof driving 100Ω loads while maintainingultra-low distortion over wide bandwidths.They offer an excellent spurious-freedynamic range (SFDR): -88dBc or betterbelow 5MHz and -59dBc at 100MHz(MAX4269). These devices operate froma single +4.5V to +8V supply or dual±2.25V to ±4.0V supplies. The inputvoltage noise density is only 8nV/√Hz,making these op amps ideal for high-performance communications and signal-processing applications that require lowdistortion and wide bandwidth.

The MAX4265 (single) and MAX4268(dual) are unity-gain-stable amplifierswith gain-bandwidth products up to400MHz. The single MAX4266 and dualMAX4269 amplifiers provide bandwidthsup to 350MHz at a minimum stable gainof +2V/V. The single MAX4267 and dualMAX4270 provide a 300MHz bandwidthat a minimum stable gain of +5V/V. Otherfeatures include a 900V/µs slew rate and±45mA output-driving capability.

For additional power savings, these ampli-fiers feature a low-power disable modethat reduces supply current and places theoutputs in a high-impedance state. TheMAX4265/MAX4266/MAX4267 come ina space-saving 8-pin µMAX package, andthe MAX4268/MAX4269/ MAX4270come in a 16-pin QSOP. Prices start at$2.05 (1000–up, FOB USA).

loop gain. The MAX4402 achieves0.009% total harmonic distortion and isunity-gain stable with capacitive loads upto 400pF.

The MAX4402 is offered in space-saving8-pin SOT23 and SO packages specifiedover the automotive temperature range (-40°C to +125°C). Prices start at $0.45(100,000–up, FOB USA).

Dual 800kHz op amp comes in tiny 8-pin SOT23 package

The MAX4402 dual, rail-to-rail op amp ina tiny 8-pin SOT23 package draws only320µA of supply current per amplifierwhile achieving an 800kHz gain-bandwidth product. Ideal in space-limitedportable and battery-powered applicationsthat require low power without sacrificingbandwidth or gain accuracy, it operatesfrom a single +2.5V to +5.5V supply. Itsoutput architecture is capable of driving a2kΩ load to within 55mV of both supplyrails while maintaining a 110dB open-

13

NEW PRODUCTSSPDT/SPST SOT23 analog switches provide ±15kV ESD protection

The MAX4561 and MAX4568/MAX4569are low-voltage, ESD-protected analogswitches. The MAX4568’s normally open(NO) inputs, the MAX4569’s normallyclosed (NC) inputs, and the MAX4561’ssingle-pole/double-throw (SPDT) inputsare protected against latchup or damage forESD up to ±15kV. Their COM inputs areprotected to ±2.5kV.

These switches operate from a single +2Vto +12V supply. For all, on-resistance(RON) is 70Ω at 5V (120Ω at 3V),matched between channels to within 2Ω(max), and flat (over the specified signalrange) to within 4Ω (max). The switcheshandle rail-to-rail analog signals, and theiroff-leakage current is only 0.5nA at +25°C(5nA at +85°C).

When operating with a 5V supply, thedigital inputs’ 0.8V to 2.4V logic thresh-olds ensure compatibility with TTL/CMOSlogic levels. The MAX4561 comes in a 6-pin SOT23 package, and the MAX4568/MAX4569 come in a 5-pin SOT23package. Prices start at $0.75 (1000–up,FOB USA).

Current-sense amplifier/comparator/ reference in tiny package simplifies over/undercurrent protection

MAX4373/MAX4374/MAX4375 micro-power devices combine a high-sidecurrent-sense amplifier, a reference, andone or two internal comparators in a tiny(3mmx5mm) µMAX (MSOP) package.By including a reference and comparatorsfor user-programmable thresholds, these

ICs vastly simplify the design ofover/undercurrent-protection circuits. Thecombination of factory-trimmed gain andexternal sense resistor allows the user toselect the full range of measured current.Three factory-trimmed gains are available:+20V/V (T version), +50V/V (F version),and +100V/V (H version).

The MAX4373T/F/H set single-currentthresholds; the MAX4374T/F/H andMAX4375T/F/H include an additionalcomparator to allow for multiple thresh-olds and over/under thresholds. Thesecond comparator can also monitor asystem supply voltage. All devices operatefrom a 2.7V to 28V supply and achieve200kHz bandwidths (AV = +20V/V)

while drawing only 60µ A of supplycurrent. Circuit architecture allows theinput common-mode voltage to rangefrom 0V to 28V, independently of thesupply voltage. Ground-sensing inputsmaintain linearity and keep the outputphase from reversing when the inputcommon-mode voltage is near ground.This feature is useful during power-up orpower-down transients and during certaininput fault conditions.

The MAX4373T/F/H is offered in space-saving 8-pin µMAX and SO packages.The MAX4374T/F/H and MAX4375T/F/Hare offered in 10-pin µMAX and 14-pinSO packages. Prices start at $1.15(1000–up, FOB USA).

5MHz, SOT23 op amp features rail-to-rail I/O operation

The MAX4321 op amp combines a 5MHzgain-bandwidth product and excellent DCaccuracy with rail-to-rail operation at theoutput and both inputs. It draws only650µA of quiescent supply current whenoperating from a single +2.4V to +6.5Vsupply or dual ±1.2V to ±3.25V supplies.(Typical operation extends as low as+1.8V or ±0.9V.) The MAX4321 remainsunity-gain stable with capacitive loads upto 500pF and is capable of driving a 250Ωload to within 200mV of either rail. Over-driven inputs do not produce an outputphase reversal.

A rail-to-rail input common-mode voltagerange and output swing make theMAX4321 ideal for low-voltage, single-supply applications. Its low input offsetvoltage (±1.2mV) and high slew rate(2V/µs) make it an excellent choice insignal-conditioning stages for precision,low-voltage data-acquisition systems.

As a low-voltage, pin-for-pin upgrade forthe LMC7101, the MAX4321 offers fivetimes the bandwidth, twice the slew rate,and approximately half the input voltagenoise density. It comes in a 5-pin SOT23package specified for the extended-indus-trial temperature range (-40°C to +85°C),with prices starting at $0.48 (1000–up,FOB USA).

2Ω quad SPST analog switchesoptimized for ±5V applications

The MAX4677/MAX4678/MAX4679quad analog switches exhibit 2Ω (max)RON when operating with ±5V supplies.RON is matched between channels towithin 0.3Ω (max), and is flat (to within0.4Ω max) over the specified signal range.Each switch handles rail-to-rail analogsignals, and off-leakage current is 0.1nA at+25°C. Ideal in low-distortion applica-tions, these switches are preferred for usein automated test equipment (instead ofmechanical relays) because they have lowoperating power, greater reliability, andrequire less board space.

The MAX4677 has four NC switches, andthe MAX4678 has four NO switches. TheMAX4679 has two of each and guaranteesbreak-before-make switching. Operatingfrom a single +2.7V to +11V supply ordual ±2.7V to ±5.5V supplies, theseswitches are ideal for use in digital cardapplications and single-ended 75Ωsystems. All feature a separate logic-voltage input (+2.7V < VL < V+) thatallows independence between the logicand analog supplies.

The MAX4677/MAX4678/MAX4679 areavailable in 16-pin DIP and TSSOPpackages, with prices starting at $1.87(1000–up, FOB USA). MAX4561

Upstream CATV amplifier outputs 66dBmV

The MAX3509 is a programmable poweramplifier for use in CATV upstream appli-cations. It operates in the 5MHz to 65MHzfrequency range, requires a single supply,and generates up to 66dBmV QPSKthrough a 1:1 transformer. Its variable gainis controlled in 1dB steps through a 3-wireserial data bus.

A transmit-disable mode places theMAX3509 in a high-isolation state,shutting down all analog functions tominimize power consumption and outputnoise between bursts in a TDMA system.(Transmit-disable mode lowers the supplycurrent to 7.8mA.) When entering andleaving this mode, transients are held to25mV nominal at full gain.

An additional power-down mode(shutdown) disables all circuitry andreduces the supply current below 1µA. The MAX3509 is available in a 20-pinTSSOP-EP package specified for theextended-industrial temperature range (-40°C to +85°C). Prices start at $4.75

Wideband, quad, 2:1 analog multiplexer has 5Ω RON

The MAX4674 is a low-voltage CMOSanalog switch containing four 2:1 multi-plexers/demultiplexers. Operating from asingle +5V supply, it exhibits a low 4Ω(max) RON. The supply range is +1.8V to+5.5V. RON matching between channels is0.4Ω, and RON flatness over the specifiedsignal range is 0.8Ω. Off-leakage current isonly 0.5nA (max) at +25°C.

The MAX4674 handles rail-to-rail signalsand offers fast operation (tON = 18ns andtOFF = 6ns). For 1MHz signals, crosstalkis -114dB and off-isolation is -67dB.Package options are the 16-pin QSOP,TSSOP, and narrow SO, with pricesstarting at $1.45 (1000–up, FOB USA).

Fast, 4-channel analog multiplexerhas 4Ω RON

The MAX4634 is a fast (30ns tON, 13nstOFF), low-voltage (1.8V to 5.5V supply),4-channel analog multiplexer with 4Ω(max) RON. RON matching betweenswitches is 0.3Ω (max), and RON flatnessover the specified signal range is 1Ω(max). Off-leakage current is only 0.1nA(max) at +25°C, and each switch handlesanalog signals in the V+ to ground range.All digital inputs have 0.8V and 2.4Vthresholds to ensure TTL/CMOS compati-bility.

The MAX4634 comes in a 10-pin µMAXpackage, with prices starting at $0.95(1000–up, FOB USA).

14

NEW PRODUCTSLow-voltage, High-speed SPST/SPDT analog switches have RON ≤4Ω

The MAX4641 and MAX4651 families ofanalog switches operate from a single+1.8V to +5.5V supply. The dual single-pole/single-throw (SPST) MAX4641/MAX4642/MAX4643, single-pole/double-throw (SPDT) MAX4644, andquad SPST MAX4651/MAX4652/MAX4653 switches have 4Ω (max) RONwith a 5V supply (8Ω with a 3V supply).The single SPST MAX4645/MAX4646have 2.5Ω RON with a 5V supply. Allproducts feature RON matched betweenchannels to within at least 0.6Ω and flat to within at least 1Ω over the specifiedsignal range. The switches offer fastswitching speeds: tON = 18ns (typ) andtOFF = 12ns (typ). Off-leakage current is≤0.1nA at +25°C, and quiescent powerconsumption is ≤0.01µW. AC characteris-tics are excellent: ≤-100dB crosstalk at1MHz, ≤-80dB off-isolation at 1MHz, and0.018% THD.

The MAX4641 has two normally open(NO) switches, the MAX4642 has twonormally closed (NC) switches, and theMAX4643 has one of each. TheMAX4645 is a NO switch, and theMAX4646 is a NC switch. The MAX4651has four NC switches, the MAX4652 hasfour NO switches, and the MAX4653 hastwo of each. All MAX4641 familydevices are available in a small 8-pinµ MAX package, or a 6-pin SOT23(MAX4644/MAX4645/MAX4646 only)or 5-pin SOT23 (MAX4645/MAX4646only), with prices starting at $0.60(1000–up, FOB USA). All MAX4651family devices come in 16-pin SO andTSSOP packages, with prices starting at$1.20 (1000–up, FOB USA).

10Ω, SPST CMOS analog switches in SC70 package

The MAX4594–MAX4597 are single-pole/single-throw (SPST) CMOS analogswitches that operate from a single +2.0Vto +5.5V supply. MAX4594/MAX4596switches are NO, and MAX4595/MAX4597 switches are NC. MAX4596/MAX4597 pinouts are optimized toprovide the highest off-isolation availablein an SC70 package.

Each switch guarantees 10Ω (max) RON(5V operation), and 1.5Ω (max) flatnessover the analog signal range. All offer lowleakage current (0.5nA off-leakage), -80dB off-isolation at 1MHz, 5pC (max)charge injection, and fast switching (tON =35ns max, tOFF = 40ns max). MAX4594–MAX4597 switches are available in a 5-pin SC70 package, with prices starting at$0.53 (1000–up, FOB USA.

NO

INGND

1 5 V+COM

MAX4594

2

3 4

15

NEW PRODUCTS1A linear regulator offers low dropout and low IQ

The MAX1793 LDO operates from 2.5Vto 5.5V and delivers a guaranteed 1A loadcurrent with a low 210mV dropoutvoltage. The high-accuracy output voltage(±1%) is preset to 5V, 3.3V, 2.5V, 2V,1.8V, or 1.5V, or can be adjusted with anexternal resistor divider.

An internal PMOS pass transistor allowsthe MAX1793 to draw only 125µA ofsupply current, making it ideal for use inbattery-powered equipment. Shutdowncurrent is 0.1µA, and output noise is only115µVRMS. Other features include a built-in reset output, low-power shutdown, andprotection against short circuits andthermal overload. The MAX1793 comes ina 1.5W, 16-pin power TSSOP package,which is only 1.1mm high and 30%smaller than a SOT223 package. Pricesstart at $1.50 (1000–up, FOB USA).

Linear regulator in µMAX packagehas 130mV dropout at 500mA

The MAX1792 low-dropout linear regulator(LDO) operates from a 2.5V to 5.5V supplyand delivers a guaranteed 500mA loadcurrent with low 130mV dropout voltage.The output voltage has high accuracy(±1%). It comes preset to 1.5V, 1.8V, 2.5V,3.3V, or 5V, or can be adjusted from 1.25Vto 5.0V with an external resistor divider.

An internal PMOS pass transistor allowsthe low supply current (80µA) to remainindependent of load, making this deviceideal for portable battery-operatedequipment, such as personal digital assis-tants (PDAs), cellular phones, cordlessphones, base stations, and notebookcomputers.

Other features include an active-low, open-drain reset output with 4ms timeout period(indicating when the output is out of regu-lation), a 0.1µA shutdown mode, andshort-circuit and thermal-overload protec-tion. The MAX1792 comes in a miniature,1.3W, 8-pin power-µMAX package withmetal pad underneath. Prices start at $1.15(1000–up, FOB USA).

12V, low-dropout linear regulatorshave low 2µA IQ

The MAX1725/MAX1726 are linear regu-lators ideal for low-power applicationsthat demand the longest possible batterylife. These devices offer ultra-low supplycurrent (2µA) and low dropout voltage.Unlike PNP-based designs, the MAX1725/MAX1726 have PMOS pass elements that

maintain an ultra-low 2µA supply currentthroughout their operating range,including dropout. Despite their lowpower consumption, they have tightoutput accuracy (1.5%), and they achievegood load-transient response with just 1µFof output capacitance.

The wide input voltage range ofMAX1725/MAX1726 regulators (2.5V to12V) makes them an excellent choice forsystems powered by a 9V battery or bytwo Li+ cells. The regulators include

protection against reversed batteries, shortcircuits, and high temperature. Outputcurrents are guaranteed to 20mA.

The MAX1725 output is adjustable from1.5V to 5V using an external resistordivider, and the MAX1726 comes with itsoutput factory preset to 1.8V, 2.5V, 3.3V,or 5V. Both devices come in a miniature5-pin SOT23 package, with prices startingat $0.82 (1000–up, FOB USA).

High-powerstep-up DC-DC converter integrates 10A switch

The MAX1709 step-up DC-DC convertersets a new standard of space savings forhigh-power devices of its type. Packing a22mΩ, 10A power MOSFET in a small16-pin narrow SO package, it delivers upto 4A of output current (20W) whenstepping up from 3.3V to 5V. It acceptsinputs in the 0.7V to 5V range, and gen-erates either a fixed 3.3V or 5V, or anadjustable output in the 1.25V to 5V range.

For applications that require less than full-power capability, the MAX1709’sprogrammable soft-start and currentlimiting let you save size and cost byscaling down the external components.Low quiescent power consumption(<1mW) extends the MAX1709 operatingtime in battery-powered systems. Inaddition to conventional on/off logiccontrol, two on/off control inputs allowsimple push-on/push-off control through amomentary pushbutton switch.

By constraining the switching-noisespectrum to the 600kHz fundamental andits harmonics, the MAX1709’s fixed-frequency PWM operation enables easypostfiltering for noise reduction. For eventighter control of the noise spectrum, youcan synchronize the clock to an externalfrequency in the 350kHz to 1MHz range.

Preassembled evaluation kits with recom-mended components are available to helpreduce design time. The MAX1709 isspecified for the extended-industrial temper-ature range (-40°C to +85°C), with pricesstarting at $3.57 (1000–up, FOB USA).

NC

MAX1792

IN

IN

ON

OFF

CIN1µF

SHDN

OUT

OUT

RST

GNDSET

COUT3.3µF

VOUT

TO µC

VIN = 2.5V TO 5.5V

RRST100kΩ 0

100

50

200

150

250

300

0 600 800200 400 1000 1200

DROPOUT VOLTAGE vs. LOAD CURRENT

MAX

1793

toc0

7LOAD CURRENT (mA)

DROP

OUT

VOLT

AGE

(mV)

16

NEW PRODUCTS

MicroCap, low-dropout linear regulator delivers 1A

The MAX8869 LDO operates from a 2.7Vto 5.5V input and delivers a guaranteed 1Aload current with 200mV dropout. Its ±1%accurate output voltage level is preset at thefactory for 5V, 3.3V, 2.5V, 1.8V, or 1.0V,or is adjustable from 0.8V to 5V using anexternal resistor divider.

Internal MicroCap™ technology providesstability using only a small 1µF outputcapacitor. The internal PMOS pass tran-sistor provides exceptionally low 200mVdropout voltage at 1A and suits the devicefor use in networking and telecomhardware as well as battery-operatedequipment. Other features include soft-start capability, low-power shutdown,short-circuit protection, and thermal-shutdown protection. The MAX8869 isavailable in a 1.7W, 16-pin TSSOPpackage, only 1.1mm high and 30%smaller than a SOT223. Prices start at$1.65 (1000–up, FOB USA).

MicroCap is a trademark of Maxim IntegratedProducts.

LDOs feature ultra-low IQ and POK

The MAX8880/MAX8881 LDOs haveultra-low supply currents of 3.5µA, yetare capable of delivering up to 200mA.These low-dropout devices operate withinputs up to 12V and feature automaticreverse-battery protection, making themideal for applications that require longbattery life.

Low supply current extends battery life inapplications with long standby periods.Unlike PNP-based designs, these maintainultra-low supply current throughout theoperating range and in dropout. Theyinclude protection against output shortcircuits, reverse-battery connections, andthermal overload. An internal power-OKcomparator (POK) indicates when theoutput is out of regulation.

The MAX8880 output is adjustable from1.25V to 5V using an external resistordivider. The MAX8881 provides factory-preset output voltages of 1.8V, 2.5V,3.3V, or 5V. Both are available in aminiature 6-pin SOT23 package, withprices starting at $0.86 (2500–up, FOBUSA).

Smallest 5th-order filters have lowest power

The MAX7426/MAX7427 5th-order,switched-capacitor, lowpass elliptic filtersare available in 8-pin µMAX and DIPpackages. The proprietary µMAX package,80% smaller than an 8-pin DIP, providesthe smallest 5th-order switched-capacitorfilters available. They operate from a singlesupply of 5V (MAX7426) or 3V(MAX7427), while drawing only 0.8mA ofsupply current. While in shutdown, thequiescent current drops to 0.2µA. Low cost,small size, and low power make thesefilters ideal for cost-sensitive portableequipment that requires post-DAC or anti-aliasing filtering.

The MAX7426/MAX7427 provide 37dBstopband rejection with sharp rolloffs and a1.25 transition ratio. Corner frequencies are clock tunable from 1Hz to 9kHz(MAX7426) and 1Hz to 12kHz (MAX7427).Two clocking options are available: self-clocking by means of an external capacitor,or external clocking (for tighter control ofthe cutoff frequency). The offset adjust pincan either null the output offset (4mV typ)or introduce a DC level shift at the output.

The MAX7426/MAX7427 are specifiedfor the commercial (0°C to +70°C) orextended-industrial (-40°C to +85°C)temperature range, with prices starting at$0.70 (100,000–up, FOB USA).

World’s smallest power ICs for CDMA handsets

The MAX1798/MAX1799 system powersupplies are designed specifically forCDMA cellular/PCS handsets and arecompatible with a variety of CDMAchipsets. Each IC includes five low-noiseLDOs, a serial interface for controlling andprogramming the output voltages, a resettimer (140ms min), a watchdog input,optional push-on/push-off power control,and two high-current, open-drain outputsfor driving a vibrator motor and/or LEDs.The two devices differ only in their serialinterface: the MAX1798 is compatiblewith the 3-wire SPI interface, and theMAX1799 is compatible with the 2-wireI2C™ interface.

The main regulator output (LDO1) is ratedfor 300mA, and the other four are rated for150mA. All are optimized for high

accuracy, high channel-to-channel isolation,low noise, and low dropout voltage. Attwo-thirds of rated output current, thedropout voltage is 75mV for LDO1 and50mV for LDO2–LDO5. Each outputvoltage can be independently enabled,disabled, and programmed (to any of 32levels from 1.8V to 3.3V) through theserial interface. For added protection, eachLDO includes independent current limitingand thermal overload circuitry.

The MAX1798/MAX1799 package—a2.1W, space-saving 20-pin TSSOPspecified for the extended-industrialtemperature range (-40°C to +85°C)—makes these devices the most compactavailable for CDMA handset applications.Prices start at $2.30 (1000–up, FOBUSA). Software and a preassembled eval-uation kit (MAX1799EVKIT) areavailable to help reduce design time.

I2C is a trademark of Philips Corp.

17

NEW PRODUCTSStand-alone switchmode controller charges Li+ batteries

The MAX1737 switchmode controllercharges one to four Li+ cells in series. Itprovides a regulated charging current andcharging voltage, with a total voltage errorof only ±0.8% at the battery terminals. Anexternal N-channel switch and synch-ronous rectifier provide high efficiency forinput voltages up to 28V. The built-insafety timer automatically terminatescharging when the adjustable time limithas been reached.

Regulation of the voltage set point andcharging current is accomplished by twocontrol loops, which work together toeffect a smooth transition between voltageand current regulation. To preventoverload of the input supply and enableuse of a low-cost wall adapter, an addi-tional control loop monitors and limits thetotal current drawn from that supply.

The limit for battery-voltage regulation isset between 4.0V and 4.4V per cell, andthe number of cells is set from one to fourby pin strapping. An external thermistormonitors the battery temperature toprevent charging when this temperature isoutside the acceptable range.

An evaluation kit (MAX1737EVKIT) isavailable to help reduce design time. TheMAX1737 is available in a space-saving28-pin QSOP package, with prices startingat $2.85 (1000–up, FOB USA).

Low-powerwatchdog timers come in SOT23

The MAX6369–MAX6374 watchdog timersupervisory circuits are designed to increasesystem reliability by supervising micropro-cessor (µP) activity and detecting code-execution errors. When a system is notoperating properly, these devices signal afault condition by resetting or interruptingthe µP. Low supply current (5µA) makesthem ideal for battery-operated applications.

These watchdog timers provide 24 pin-selectable timing combinations, and the

watchdog timeout period can be adjustedfrom 1ms to 60s to accommodate mostsystems. To allow for full initialization ofthe system, a startup delay disables thewatchdog during power-up or during achange in the watchdog timeout period.Startup delays also range from 1ms to 60s.

The MAX6369–MAX6374 come in an 8-pin SOT23 package and require noexternal components, making them idealfor use in hand-held instruments and otherspace-limited systems. Other applicationsinclude embedded control systems, indus-trial controllers, and automotive systems.Prices start at $0.98 (2500–up, FOB USA)

World’s smallest Li+ battery chargerin SOT23

The MAX1736 is a stand-alone chargerfor single-cell Li+ batteries. Powered byan inexpensive current-limited wall cube,it operates with an external PFET switchin a gated control scheme that allows theentire charging circuit to remain cool—unlike circuits based on heat-producinglinear-mode regulators. It fits incellular/PCS phone handsets and low-power hand-held equipment, such asPDAs and portable digital-audio players.

The MAX1736 offers better than 0.5%accuracy for battery-regulation voltage. Itincludes a complete state machine tosafely control the charging sequence andan on-board precharge circuit thatprevents damage by charging near-deadcells prior to the fast charge. Once thebattery-regulation voltage is reached, thecell is topped off using a hystereticalgorithm. This algorithm fully chargesthe cell while eliminating errors due toseries resistance.

To accommodate a variety of wall cubesand other input supplies, the MAX1736operates with a wide 4.7V to 22V input-voltage range. It automatically detects thepresence of an input supply, and if theinput power is removed, it automaticallypowers down to minimize current drainfrom the battery. A single ENABLE pinpermits simple charge control by anoptional microcontroller (µC).

For a similar Li+ charger that includes anLED drive, internal safety counters, andthermistor temperature monitoring,consider the MAX1679 (available in an 8-pin µMAX package). The MAX1736comes in a tiny 6-pin SOT23 packagespecified for the extended-industrialtemperature range (-40°C to +85°C), withprices starting at $1.50 (1000–up, FOBUSA). A preassembled evaluation kit withrecommended external components(MAX1736EVKIT) is available to helpreduce design time.

Quad voltage monitor requires no external components

The MAX6338 quad voltage monitor isdesigned to monitor multivoltage systemsin telecommunications, networkingequipment, storage devices, high-endprinters, and computers. When a monitoredvoltage falls below its preset threshold, thecorresponding open-drain output notifiesthe system by asserting an active-lowsignal. The monitor deasserts when theinput voltage rises above the threshold.

A variety of voltage thresholds and toler-ances are available to accommodate thestandard logic levels found in today’sapplications. These preset thresholdoptions include +5.0V, +3.3V, +3.0V,+2.5V, +1.8V, and -5V. User-adjustableoptions are also available to monitorvoltages different than those listed above.Voltages of +5.0V, +3.3V, +2.5V, and+1.8V can be monitored without addingexternal components.

The internally trimmed thresholds andweak internal pullups to VCC minimize theneed for external components. To providean easy interface to other devices, the fourindependent open-drain outputs can beoverdriven by external voltages rangingfrom 0V to +5.5V.

The MAX6338 operates from 2.5V to5.5V and draws only 25µ A of supplycurrent. It is available in a small 10-pinµMAX package fully specified over theextended temperature range. Prices start at$2.50 (1000–up, FOB USA).

18

NEW PRODUCTSTriple RS-485 receivers include fault detection and ±15kV ESD protection

The MAX3097E/MAX3098E triple RS-422/RS-485 receivers target motor-controlapplications. Each receiver has an indepen-dent alarm output that warns of fault condi-tions at the receiver inputs. This alarm isasserted when the receiver inputs areshorted, open, out of their common-moderange, or have a low differential voltage.The MAX3097E and MAX3098E (A andB grades) differ in the accuracy of theirdifferential fault thresholds. The devicesalso feature capacitor-programmable,delayed-alarm outputs to ensure error-freefault detection even at slow transition rates.

The MAX3097E/MAX3098E operate froma single 3.0V to 5.5V supply and guaranteedata transfers up to 32Mbps. To ensurecompliance with strict international ESDrequirements, the receiver inputs are ESDprotected up to ±15kV using the IEC 1000-4-2 Air-Gap Discharge method, to ±8kVusing the IEC 1000-4-2 Contact Dischargemethod, and to ±15kV using the HumanBody Model.

MAX3097E/MAX3098E devices areavailable in space-saving 16-pin QSOP,SO, and DIP packages specified for thecommercial and extended temperatureranges. Prices start at $3.56 (1000–up, FOBUSA).

Tiny, ultra-low-power SC70 voltage detectorsideal for portableequipment

The MAX6375–MAX6380 voltagedetectors monitor battery, power-supply,and regulated system voltages. Eachdetector contains a precision bandgapreference, comparator, and internallytrimmed resistors that set specified tripthreshold voltages. By monitoring nominalsystem voltages from +2.5V to +5.0Vwithout the need for external componentsor adjustments, they also provide excellentcircuit reliability and low cost.

The voltage detectors are differentiated bytheir output logic configurations and presetvoltage thresholds. The MAX6375/MAX6378 (push-pull) and MAX6377/MAX6380 (open-drain) devices haveactive-low outputs. The MAX6376/MAX6379 have active-high push-pulloutputs. The MAX6375/MAX6376/MAX6377 provide voltage thresholdsbetween 2.20V and 3.08V, in approximateincrements of 100mV. The MAX6378/MAX6379/MAX6380 have voltage thresh-olds between 3.30V and 4.63V in approxi-mate 100mV increments.

Ultra-low supply current (500nA) makesthe MAX6375/MAX6376/MAX6377 idealfor use in portable equipment. All sixdevices are available in a miniature SC70package, with prices starting at $0.90(2500 or 10,000 piece minimum, FOB USA).

New SC70 power-on reset ICs include manual reset

The MAX6711/MAX6712/MAX6713 µPsupervisory circuits monitor supply railsof 2.5V to 5V in µP and digital systems.Available in the miniature 4-pin SC70package (half the size of a SOT package),they reduce cost by eliminating externalcomponents and adjustments. Each devicealso includes a debounced manual-resetinput.

Theses ICs feature 2.5% reset-thresholdaccuracy over temperature. When supplyvoltage declines below the devicethreshold, the device asserts a reset signaland maintains it for at least 140ms afterVCC returns above the reset threshold (oruntil the manual reset is deasserted). TheMAX6711 has a push-pull active-lowreset output, the MAX6712 has a push-pull active-high reset output, and theMAX6713 has an open-drain active-lowreset output. These ICs draw only 12µAsupply current, and the reset outputs areguaranteed valid to 1.0V.

Prices start at $0.98 (2500 or 10,000 pieceminimum, FOB USA).

First backup-battery reset ICs with chip-enable gating in SOT packages

The MAX6365–MAX6368 are µP-super-visory ICs for digital systems that monitorsupply rails in the 2.5V to 5.0V range,with ±2.5% reset-threshold accuracy overtemperature. When VCC falls below thereset threshold, reset is asserted and main-tained for at least 150ms after VCC risesabove the reset threshold. If VCC fallsbelow the reset threshold and is also lessthan the battery backup voltage, the outputautomatically switches from VCC to thebackup battery to power the system RAMand/or real-time clock (RTC). Chip-enablegating write-protects the RAM data duringthese conditions.

These ICs are the first such devices withchip-enable gating available in SOTpackages, which are approximately 70%smaller than alternative packages.Miniature packages and low supplycurrent (10µA) make the parts ideal forportable applications. All devices areavailable with a push-pull active-low resetoutput, open-drain active-high resetoutput, or open-drain active-low resetoutput. Additional functionality includes amanual-reset input (MAX6365), watchdoginput (MAX6366), battery-on output(MAX6367), and auxiliary-reset input(MAX6368). Available in an 8-pin SOTpackage, they draw only 10µA of supplycurrent. Prices start at $1.88 (2500–up,FOB USA).

ENCODED SIGNALS

A, A, B, B, Z, Z

MOTOR DRIVER

MOTOR

MOTORCONTROLLER

ALARMOUTPUTS

RECEIVEROUTPUTS

DSP

8

MAX3097EMAX3098E

MAX54712-BIT D/A

19

NEW PRODUCTStransmitting high-speed clock and datasignals: to 10Mbps in V.11 or V.35 modes,and to 240kbps in V.28 mode. TheMAX3171/MAX3173 are also 3Tx/3Rxtransceivers, but they transmit lower speedcontrol signals. The MAX3172/MAX3174contain five termination networks designedfor use with the MAX3170, plus a fourthtransceiver for transmitting control signals.

The MAX3171/MAX3172 receiver inputshave 10µs deglitching circuitry that enablesunterminated operation. All devices havetrue fail-safe receiver inputs that guaranteelogic high outputs when the bus is idle or when the inputs are open or shorted. The MAX3170, MAX3171/MAX3173,and MAX3172/MAX3174 are available ina 28-pin SSOP package, with prices for thecomplete 3-piece chipset starting at $18.33(1000–up, FOB USA).

*Future product

MUX 16

-BIT

ADC 12

-BIT

DAC

RISC

µP

AMP OUT

ANALOGOUT

DIGITALOUT

ANDSAVE

SPACE WITH...

ELIMINATE COSTLY COMPONENTS

2.4V

OP AMP

EEPROMTEMPSENSOR

PGA

MAX1462

Complete 3.3V multiprotocol chipset supports V.10, V.11, V.28, and V.35 protocols

The MAX3170, MAX3171/MAX3173*,and MAX3172/MAX3174* form a multi-protocol chipset. This chipset is ideal fornetworking applications, such as switchesand routers, that require compatibility withmany different protocols from a singleconnector. The chipset provides pin- andsoftware-selectable DCE and DTE portscompatible with protocols such as V.10,V.35, V.28 (RS-232), and V.11 (RS449/V.36, EIA530, EIA530-A, X.21). Inaddition to these standards, the deviceshave undergone compliance testingperformed and verified by an outside testfacility and compatible with the NET1,NET2, TBR-1, and TBR-2 telecommunica-tion standards.

Single +3.3V supply operation makes thischipset ideal for low-voltage systems. TheMAX3170 is a 3Tx/3Rx transceiver for

1µA, 460kbps, RS-232-compatible transceiver has ESD protection to ±15kV

The MAX3314E is a ±5V poweredtransceiver compatible with the EIA/TIA-232 standard. Its flow-through architecturefeatures one transmitter and one receiver,protected to ±15kV using IEC 1000-4-2Air-Gap Discharge, to ±8kV using IEC1000-4-2 Contact Discharge, and to ±15kVusing the Human Body Model.

The transmitter’s low-dropout output stageprovides ±3.7V (min) RS-232-compatibleoutput levels, while driving a load of 3kΩand 1000pF at 460kbps. Supply voltages of+5V and -5V must be provided externally.The MAX3314E’s SHDN input enablesan external signal to disable and three-statethe transmitter (receiver remains active),while reducing the supply current to 1mA.The MAX3314E is available in 8-pinµ MAX and SO packages, with pricesstarting at $1.18 (1000–up, FOB USA).

16-bit signalconditioner for smart sensorsoperates at 2.4V

The low-power MAX1462 is a highly inte-grated, 16-bit signal conditioner for smartsensors, capable of digitally correctingsensor outputs over a wide temperaturerange. It operates at 2.4V and draws only310µA of supply current.

Internal to the chip is an RISC µ P,EEPROM, 16-bit ADC, 12-bit DAC,programmable-gain amplifier (PGA),temperature sensor, and auxiliary op amp.To produce the conditioned output, theDSP combines the digitized input signal,temperature-sensor output, and user-programmed calibration coefficients storedin the internal EEPROM. The result isavailable both as a 12-bit digital word andas a ratiometric analog voltage generated bythe internal 12-bit DAC. The uncommittedop amp can be used for filtering the analogoutput or implementing a 2-wire, 4–20mAtransmitter. The high-precision front end,

which includes a 16-bit ADC, 2-bit PGA,and 3-bit coarse-offset DAC, resolvesdifferential input signals below 1µV.

The MAX1462 is perfect for hand-held,low-power applications such as pressuresensors, humidity sensors, and smartbatteries. It is readily adaptable for use inautomotive, industrial, and medical appli-cations as well. Test features built into theMAX1462 are designed to automate andintegrate the pretest, calibration, compensa-tion, and final-test operations of traditionalsensor manufacturing. By eliminatingmanual calibration methods, the devicesaves significant manufacturing costs.

A dedicated cell library of more than 500sensor-specific functional blocks enablesMaxim to quickly customize theMAX1462 for unusual requirements asso-ciated with high-volume applications. TheMAX1462 is available in a space-saving,9mmx9mm 48-pin TQFP package. Pricesstart at $6.50 (1000–up, FOB USA).

20

NEW PRODUCTS

3.3V smart regulator for PCI-compliant NICs requires only 1µF output capacitor

The MAX1810 smart regulator is suitablefor use in Ethernet network interface cards(NICs), modem cards, and other devicescompliant with peripheral componentinterconnect (PCI) components. TheMAX1810 delivers an uninterrupted 3.3V,with output currents up to 500mA, from a5V main supply, a 5V standby supply, or a3.3V auxiliary supply. When the main andstandby supplies both drop below 4.1V, aninternal switch connects the PCI system’s3.3V auxiliary input to the MAX1810

Current-limiting hot-swap controllers include autoretry and DualSpeed/BiLevel fault protection

The MAX4271/MAX4272/MAX4273 ICsmake up a complete family of integrated3V to 12V hot-swap controllers. Theyenable safe insertion and removal ofcircuit cards from a live backplane.Because the circuit card’s discharged filtercapacitors provide a low impedance to thelive backplane, high-level inrush currentsfrom backplane to circuit card can burn upconnectors and components, or cause asystem reset by momentarily collapsingthe backplane power supply. By regu-lating inrush current to a preset limit,these hot-swap controllers allow thesystem to stabilize safely.

After the startup cycle is completed, twointernal comparators provide DualSpeed/BiLevel™ protection against shortcircuits, load glitches, and overcurrents.The ICs respond to faults by discon-necting the load. They handle faultrecovery by unlatching (MAX4271),autoretry (MAX4272), or programmingmethods (MAX4273).

Additional features include an internalcharge pump that provides gate drive foran external N-channel FET, startupcurrent regulation, and current-glitchprotection. Open-drain status outputsindicate fault conditions.

The MAX4271 with latched fault protec-tion and the MAX4272 with autoretry faultprotection are available in a space-saving 8-pin SO package, and the full-functionMAX4273 comes in 16-pin QSOP and SOpackages. All devices are specified for theextended-industrial temperature range (-40°C to +85°C) and have an absolutemaximum rating of 15V for extra protec-tion against inductive kickback duringboard removal. Prices start at $1.95(1000–up, FOB USA).

DualSpeed/BiLevel is a trademark of MaximIntegrated Products.

Low-voltage SIM/smart-card level translators in µMAX package

The MAX1840/MAX1841 are level trans-lators for smart cards and subscriberidentity modules (SIMs). They providelevel shifting and protection against ESDfor SIM and smart-card ports. The devicesintegrate two unidirectional level shiftersfor the reset and clock signals, a bidirec-tional level shifter for the serial datastream, and ±10kV ESD protection for allcard contacts.

The MAX1840 SHDN control input aidsinsertion and removal of SIM and smartcards, and the MAX1841 system-side data

Low-dropout, 20ppm/°C SOT23 references deliver 5mA and require no output capacitors

The MAX6061–MAX6067 family ofthree-terminal, series-mode precisionvoltage references can save board space byoperating without an output capacitor.Otherwise, they remain stable withoutput/load capacitors as high as 1µF.These seven new devices have output

driver supports system controllers that lackopen-drain outputs. Logic-supply voltageranges are 1.4V to 5.5V for the controllerside and 1.7V to 5.5V for the card side.Total supply current is 1.0µ A. Bothdevices shut down automatically wheneither supply voltage is removed. For acomplete SIM card interface, combine the MAX1840 or MAX1841 with theMAX1686H regulated charge pump,which provides 0V, 3V, and 5V outputs.

The MAX1840/MAX1841 are compliantwith GSM test specifications 11.11 and11.12. They are available in an ultra-small10-pin µ MAX package that is only1.09mm high and occupies half the area ofan 8-pin SO. Prices start at $1.55(1000–up, FOB USA).

output. Low resistance in this internalswitch (only 0.18Ω) minimizes voltagedrop from the auxiliary supply.

The main and standby inputs generate the3.3V output through CMOS linear regula-tors that feature excellent line and loadregulation. Their stability is guaranteed bya 1µF ceramic output capacitor, and theshort-circuited output current is limited to900mA. Thermal-overload protection turnsthe MAX1810 off when the chip tempera-ture exceeds +170°C. Special circuitry alsoprevents a flow of reverse current from theoutput to any inactive or low-voltage input.

The MAX1810 is available in a compact,high-power (capable of dissipating 0.9W),8-pin SO package specified for theextended-industrial temperature range (-40°C to +85°C). Prices start at $1.251000–up, FOB USA).

voltages of 1.250V, 2.048V, 2.500V,3.000V, 4.096V, 4.500V, and 5.000V.Each is available in two grades of outputtemperature coefficient (20ppm/°C or30ppm/°C), with initial accuracy grades of0.2% and 0.4%.

Quiescent supply currents are low (90µA)and virtually immune to voltage variations,making these SOT23 voltage referencesideal for battery-powered instruments.Usable as precision voltage regulators, theMAX6061–MAX6067 references cansource 5mA of load current and sink 2mA.Prices start at $1.35 (1000–up, FOB USA).

21

NEW PRODUCTS3-pin SC70 voltage references are smallest available

The LM4040/LM4041 are shunt-mode, 2-terminal precision voltage references. Idealfor space-critical portable applications,they fit in a 3-pin SC70 package thatrequires 40% less space than the alreadytiny 3-pin SOT23 package.

Advanced design ensures stability with anycapacitive load, yet also ensures ease of useby eliminating the need for an externalstabilizing capacitor. For an LM4041-1.2,the minimum operating current is 60µA,and the maximum is 12mA.

To ensure that the prime (A grade) partshave an accuracy better than ±0.1% at+25°C, the reference voltage is trimmedduring wafer sort using fuse and zener-zaptechniques. Each device offers four grades(A, B, C, and D). The highest (A grade)has 0.1% initial accuracy, B grade has0.2%, and C grade has 0.5%. All have a100ppm/°C tempco guaranteed from -40°Cto +85°C. The low-cost D-grade deviceshave 1% initial accuracy with 150ppm/°Ctempco.

The LM4041 has a fixed breakdownvoltage of 1.225V, and the LM4040versions have breakdown voltages of2.048V, 2.5V, 3.0V, 4.096V, and 5.0V.Prices start at $0.45 (1000–up, FOB USA)

First SOT23 dual-temperature comparators need no external components

The MAX6505–MAX6508 family of dualthermal comparators is the latest additionto an industry-leading line of temperatureswitches. These ICs are the smallest andlowest power dual-temperature switchesavailable.

Combining two temperature comparatorson a single chip, each device simplifiesthe incorporation of reliability-enhancingtemperature-control, protection, andwarning functions in a system. Becausetemperature thresholds are preset at thefactory, no external components arerequired to set the temperature trip points.Each device asserts an ALARM when thetemperature exceeds the factory-set triptemperature. The MAX6505/MAX6506also have a WARN output. Trip tempera-ture for the WARN output is pin selectedby the user to equal 5°C, 10°C, 20°C, or30°C below the ALARM trip temperature.

2.7Gbps multiplexer/buffersimplifies redundant systems

The MAX3781 dual multiplexer/buffer isused in redundant high-speed serial datapaths. Each half of the dual part providesa 1:2 buffer for creating duplicate output-data paths, and a 2:1 multiplexer forselecting from two alternate input-datapaths. This capability makes the deviceideal for implementing redundancy in

Dual 3.3V, 622Mbps,4:2 crosspointswitch enables flexible interconnections

The MAX3640 is a 3.3V dual-path cross-point switch for use at OC-12 (622Mbps)data rates. It can receive and transmit622Mbps LVDS signals across a backplanewith minimum jitter accumulation. Thedevice offers signal-path redundancy forcritical data streams, making it ideal forSONET/SDH backplanes, digital cross-connects, and high-speed parallel links.

Each path in the MAX3640 incorporatesinput buffers, multiplexers, a 2x2 cross-

The MAX6507/MAX6508 also have twologic outputs, OK and OVER. OKindicates whether the device temperaturefalls within the range bounded by thefactory-set upper and lower trip tempera-tures. OVER indicates when temperatureexceeds the upper trip temperature.

MAX6505/MAX6507 outputs are opendrain, and MAX6506/MAX6508 outputsare push-pull. All four devices come in a6-pin SOT23 package and operate from a+2.5V to +5.5V supply. Prices start at$0.79 (1000–up, FOB USA).

serial-backplane and system-interconnectapplications up to 2.7Gbps.

Low total output jitter (only 15ps)preserves data integrity. Signal outputlevels are 1600mV (typ) for inputs as lowas 200mV. The MAX3781 operates with a3.3V power supply and has a power-downmode that disables unused buffer outputs.

The MAX3781 dual multiplexer/buffercomes in a compact 48-pin TQFP packageand has on-chip terminations at all portscompatible with 50Ω transmission lines.Prices start at $6.49 (1000–up, FOB USA).

point switch, and output drivers. The fouroutput channels have redundant outputsfor test or fanning purposes. When fouroutput channels have been deselected, theoutput drivers power down to reducepower consumption by 165mW—a uniquepower-saving feature. Power consumptionwith four output channels enabled is only257mW. A fully differential architectureensures minimum crosstalk, signal skew,and jitter accumulation. The MAX3640exhibits only 2.8psRMS random outputjitter and 42ps deterministic output jitter.

The MAX3640 is available in a 48-pinTQFP package and operates from a 3.3Vsupply over a temperature range of 0°C to+85°C. Prices start at $9.99 (1000–up,FOB USA). An evaluation kit is available.

PARALLEL DATAOUTPUT

OPTICALTRANSCEIVER

622Mbps

SONETSOURCE A

SONETSOURCE B

622Mbps2.5Gbps

MAX3869LASER DRIVER

MAX3866TIA AND LA

MAX3876CDR

MAX38314-CHANNEL

INTERCONNECTMUX/DEMUX

MAX3640CROSSPOINT

SWITCH

22

NEW PRODUCTSDual-band SiGe LNA/mixer ICs offer adjustable gain and high linearity

The MAX2320–MAX2324 and MAX2326/MAX2327 SiGe ICs comprise high-per-formance receiver front ends that set newindustry standards for low noise and highlinearity at low supply current. Featuresinclude an LO frequency doubler(MAX2321), LO frequency divider(MAX2326), LO output buffers, adjustablegain settings for the dual low-noise ampli-fiers (LNAs), and a low-current pagingmode that extends the handset standbytime.

All devices operate with a single 2.7V to3.6V supply, with a 0.1µ A standbycurrent. One operates at cellular frequen-cies, one at PCS frequencies, and four atboth cellular and PCS frequencies (see theProduct Selector Guide available fromMaxim). To minimize intermodulationand crossmodulation in the presence oflarge interfering signals, each deviceincludes an LNA with high input third-order intercept point (IIP3). The LNA isbypassed in low-gain mode to provide ahigher cascaded IIP3 at lower current.Each device provides a low-current, high-gain mode for paging.

Internal CDMA mixers for the cellularand PCS bands have high linearity, lownoise, and differential IF outputs. The FMmixers, designed for lower current, havesingle-ended outputs. All devices come ina 20-pin TSSOP-EP (with exposedpaddle), specified for the extended-indus-trial temperature range (-40°C to +85°C).Prices start at $3.00 (1000–up, FOBUSA).

Unlike discrete designs, which require upto 15 components and long design times,the MAX2605–MAX2609 are simple touse and require only one external inductorto set the oscillation frequency.

MAX2605–MAX2609 VCOs integratevaractors, core transistors, bias circuitry,coupling capacitors, and a differentialoutput buffer in a miniature 6-pin SOT23package, offering ease of use, a smallfootprint, and low cost. The internal

varactor’s tuning range is factory tested toguarantee startup and proper operationover temperature. Depending on theoperating frequency, these devices drawbetween 2.1mA and 3.7mA of supplycurrent and achieve between -112dBc/Hzand -107dBc/Hz phase noise (at 100kHzoffset from the carrier). Prices start at$0.83 (1000–up, FOB USA).

Tiny chip-scale power amplifier for Bluetooth Class I applications

The MAX2240 is the first power amplifier(PA) designed specifically for Bluetoothradios and is also the smallest such PAavailable for Bluetooth Class I radios. The2.4GHz, 100mW device comes in a0.5mm pitch, 9-pin (3x3 array) ultra-chip-scale package (UCSP)—the latest tech-nology in RFIC packaging. It occupiesonly 16% of the space required by the 8-pin MSOP package of competitivedevices. Its +20dBm output power allowsthe user to extend radio link range to 100meters, a capability ideal for notebookPCs, cellular phones, and other Bluetoothdevices operating in changing environ-ments.

The MAX2240 is also suitable for use inHomeRF, 802.11 FHSS, and other2.4GHz proprietary ISM-band radio appli-cations. Its digital power-control function,a unique feature in the marketplace,allows the user to reduce transmit powerin four 6dB steps, down to +4dBm or less,as required in Bluetooth Power Class Ispecifications. The MAX2240 features anintegrated 50Ω input match that furtherreduces the external component count andrequired board space.

The MAX2240 operates on a single 2.7Vto 5.0V supply and draws only 105mA. A1µA low-power shutdown mode helps toreduce power consumption and extendbattery life. Prices start at $1.75 (1000–up,FOB USA). A fully assembled evaluationkit (MAX2240EVKIT) is available to helpreduce design time.

Miniature VCOs suit 45MHz to 650MHz applications

The MAX2605–MAX2609 family ofminiature VCOs is designed for IF and RFapplications such as cellular phones,wireless LANs, cordless phones, and otherequipment requiring a fixed oscillatorfrequency between 45MHz and 650MHz.

3.3V quad-port bypass IC operates at 2.125Gbps/ 1.063Gbps

The MAX3752 quad-port bypass ICconsists of four serially connected port-bypass circuits (PBCs) and a repeater thatprovides clock and data recovery (CDR). Itoperates with a single 3.0V to 3.6V supplyand is designed for use in the FibreChannel Arbitrated Loop topology.

The port-bypass circuits allow connectionto as many as four Fibre Channel L-ports,each of which can be enabled or bypassedthrough the PBC-select inputs. Additionalquad PBCs can be cascaded in applicationsthat require more than four L-ports. Tominimize the external parts count, allsignal inputs and outputs have internaltermination resistors compatible with 75Ωtransmission lines.

The MAX3752 complies with the FibreChannel jitter-tolerance requirements andis capable of recovering data signals withup to 0.7 unit intervals (UIs) of high-frequency jitter. When not needed, therepeater can be disabled to reduce powerconsumption. Frequency-lock indication isprovided by a fully integrated phase-locked loop (PLL), which does not need anexternal reference clock.

The MAX3752 is optimized for 2.125Gbpsor 1.063Gbps operation. It is packaged in a48-pin TQFP-EP (with exposed paddle),and prices start at $11.00 (1000–up, FOBUSA).

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NEW PRODUCTSTiny, 900MHz SiGe LNA offers variableIP3 and gain-step control

The 900MHz MAX2642/MAX2643 arethe world’s smallest SiGe LNAs. The firstavailable in a tiny 6-pin SC70 packagemeasuring only 2.0mmx2.1mm, they alsopack the most features in a 6-pin package:variable IP3, gain-step control, and low-power shutdown. Variable IP3 and gain-step control allow users to maximize thereceiver linearity without wasting supplycurrent. At 5mA, the NF and IP3 for thesedevices (1.3dB, 0dBm) outperforms theHP MGA-87563 GaAs PHEMT (1.9dB, -7dBm) and the Infineon BGA427 Si BJT(2dB, -5dBm).

MAX2642/MAX2643 LNAs provide17dB gain, 1.3dB noise figure, and 0dBminput IP3, using only 5mA of current. Byvarying the resistor connected to the BIASpin, you can adjust the input IP3 from -11dBm to +1dBm, while the supplycurrent varies from 2mA to 6mA. Thiscapability allows users to dial in therequired IP3 without wasting supplycurrent. The MAX2642’s 13dB gain-stepcontrol helps to extend the LNA’s dynamicrange. MAX2643 gain remains fixed. TheMAX2643 shuts down by logic control,and the MAX2642 shuts down by discon-necting the BIAS pin. Both amplifiersincorporate on-chip output matching,which reduces the number of externalcomponents.

The MAX2642/MAX2643 are ideal forcellular and cordless phone applications,PMR/SMR, 868MHz/900MHz ISM, andgeneral-purpose buffers or driver amplifiers.Both devices operate from a single 2.7V to5.5V supply. Prices start at $0.89 (1000–up,FOB USA). A fully assembled evaluationkit (MAX2642/MAX2643EVKIT) is avail-able to help reduce design time.

GPS receiver IC provides <0.5 meter accuracy and 5ns timing resolution

The MAX2740 GPS receiver IC offers thebest timing resolution (5ns) and the mostcompetitive positional accuracy (<0.5meter) in the industry. Typical GPSreceivers offer 300ns timing resolution andpositional accuracy >1 meter.

The MAX2740 is a complete GPS/GLONASS receiver from antenna todigitizer input. It allows the use of a multi-level digitizer for high receiver sensitivity

and good immunity to in-channel jammers.Including all filter losses, the total receivergain is >100dB, with >50dB of automaticgain-control range. Requiring minimalexternal components, the MAX2740 withits unique frequency plan is suitable foruse in joint GPS/GLONASS receivers.

An RF-only multichip module and severalcomplete modules that incorporate theMAX2740 are available through Parthus,Ltd. (See www.parthus.com.) MAX2740devices come in a small 48-pin TQFPpackage with exposed paddle, whichprovides optimum high-frequency perfor-mance. Prices start at $13.90 (100–up,FOB USA).

1.8GHz to 2.5GHz direct-conversion receivers simplify wideband WLL designs

MAX2700/MAX2701 ICs are the firstavailable direct-conversion receiversdesigned for wideband wireless local-loop(WLL) systems. (This architecture allowssingle-chip integration by eliminating theIF SAW filter, RF downconverter, and IFVCO components.) Direct conversion(zero-IF) architectures reduce cost andcomponent count by eliminating one ortwo of the frequency downconversionstypically found in today’s superhetero-dyne systems. They also improve systemreliability and manufacturing yield—twokey factors in lowering the cost of WLLsubscriber equipment. When combinedwith MAX2720/MAX2721 direct I/Qtransmitters, they form a complete chipsetfor WLL systems operating in the1.8GHz, 1.9GHz, 2.1GHz, 2.3GHz, and2.4GHz frequency bands, with channelbandwidths exceeding 50MHz.

The MAX2700 is optimized for operationin the 1.8GHz to 2.1GHz band, and theMAX2701 is optimized for the 2.1GHz to2.5GHz band. Both receiver ICs includethree main blocks: LNA, quadraturedownconverter, and baseband variablegain amplifiers (VGAs). The LNAprovides 17dB gain, 2.3dB noise figure,and +4dBm input IP3 at 2.4GHz. (High

input IP3 helps minimize cross modula-tion and gain compression due to high-level RF interference.)

The quadrature downconverter consists oftwo highly linear double-balanced mixersdriven by an external LO, a selectable LOdoubler, and a wideband LO quadraturegenerator. The double-balanced mixersare optimized for high input IP2, IP3, andminimum added noise. The MAX2701provides a mixer input IP2 of +38dBmand an IP3 of +6dBm. The high input IP2helps to minimize desensitization in thereceiver, caused by in-band AM-modulated high-level interferers.

The two baseband VGAs in each channelprovide 80dB of total maximum gain and>60dB of gain control. External lowpassfilters connected in the baseband inter-stages provide the necessary channelselectivity. Integrated into theMAX2700/MAX2701 is an amplitude/gain-correction loop, which guarantees thematch between I and Q channel ampli-tudes to be <0.7dB.

The MAX2700/MAX2701 are alsosuitable for 2-way MMDS and 2.4GHzISM wideband systems. Both ICs areavailable in a small 48-pin TQFP packagewith exposed paddle, which optimizeshigh-frequency performance. Prices startat $4.95 (1000–up, FOB USA). A fullyassembled evaluation kit (MAX2700/MAX2701EVKIT) is available to helpreduce design time.

RF INPUT

C1

L1

VCC

VCC

47pF

RBIAS

RF OUTPUT

GAINCONTROLBIAS

MAX2642